
He was born hearing in N. Dakota, then became deaf as an infant due to spinal meningitis. As a young child he enjoyed drawing and showed some skill using colored pencils. His earliest memories of sculpting was after a rainstorm when he made animal shapes out of the mud on his farm.
He was raised orally by his parents who worked with him on vocalization exercises after doing farm chores each day. At the age of 12 his family moved to Minnesota, where he was able to attend the Minneapolis Day School for the Deaf. Then he went to public high school and graduated with honors. From there he earned a B.A. cum laude from the University of Minnesota. Then he received a full scholarship to the Minneapolis School of Fine Arts. Next, he went to the Cranbrook Academy of Art in Michigan and finally the Chicago Institute of Art.

In 1938, Arnold took a professorship at Monticello College in Illinois and remained teaching there for thirty-four years, while working on art commissions. Of teaching he said, "Communication with my students has never been a serious problem. At our first meeting I tell the students that by the end of the first or second week I will be able to read their lips if they move their lips a bit slower, and that they will understand me as they get used to my way of speaking." Arnold received many prestigious awards and recognitions for his work over the years. Most of it had religious themes and can be found in churches throughout the Midwest. Other works are in schools or downtown St. Louis.
Some of his sculptures incorporated deaf themes. "Because I am deaf, I am a better observer." he once said. One of his deaf sculptures called The Learners is a depiction of a mother practicing speech exercises with her deaf child. Another, called Deaf Given A Voice portrays an eye and an arm with moving fingers to represent how Deaf people use both their eyes and hands to communicate. Though Arnold never learned ASL or even fingerspelling, he was an advocate of Total Communication- the concept of using any and every possible means to communicate with a deaf/Deaf child.
Reading over the articles I found and writing this short sketch of his life, I got a sense that Hillis Arnold considered himself an artist first, not D/deaf first. His deafness was part of who he was, but not his main identity. It seems he was too busy teaching and creating sculptures to think much about his deaf experience. Still he acknowledged his deafness in some of his art when appropriate to do so. I like this about him.